测量不确定度为一度量衡学的名词，为一个非负值的参数，表示一量测量的统计分布程度。不确定度有其统计学的基础，表示对一物理量还有一些无法完全了解的部份。所有的量测都有其不确定性，量测值需伴随其对应测量不确定度，才是完整的量测结果。

像标准差，或是给定置信水平的区间半宽度等参数都可以用来表示测量不确定度。

国际食品法典委员会的CAC/GL 54-2004是有关测量不确定度的指引。

In metrology, measurement uncertainty is a non-negative parameter characterizing the dispersion of the values attributed to a measured quantity. All measurements are subject to uncertainty and a measurement result is complete only when it is accompanied by a statement of the associated uncertainty. By international agreement, this uncertainty has a probabilistic basis and reflects incomplete knowledge of the quantity value.